Tuesday, 1 April 2014


Global Warming brings "aliens" to Paxton Pits Nature Reserve

April 1st 2014

Non-native and invasive species bring well-known threats to our gardens, rivers and nature reserves. Think of Canadian pond-weed, New Zealand stonecrop, Japanese knotweed, French lettuce, German weasels and Himalayan balsam, all of which occur at Paxton Pits Nature Reserve. Through globalisation, plants and animals from temperate areas in both hemispheres have been able to colonise us but, now that we have climate change, the chances of colonisation by species from warmer countries is becoming more of a threat. Over the last few summers we have seen sub-tropical species like red-eared terrapins and catfish in our ponds, so what animals could we expect next?

There is now a substantial local trade in tropical pets, including snakes such as boa constrictors and reptiles such as alligators. We actually found a boa-constrictor on the reserve in 2013, but it was dead. (We think it choked on a hedgehog.) Alligators and pirañas are pretty hard to see, even in their native Amazonian wetlands, but are they here already? We see a lot of wading birds and ducks with one leg missing, so something is biting their feet off in the water. We also see a lot of dead swans so we do not think that pike are the only large predators in our lakes, indeed, I found the head of a huge pike on the Reserve that had been eaten by someting even bigger. Several quite large dogs have gone missing after their owners threw sticks into the lakes for them to retrieve.

Please help us by not dumping unwanted pets or garden waste on our nature reserve and protect yourselves by keeping well away from the water's edge, especially in summer when warm-water species such as alligators and snapper turtles are likely to be active. If you are attacked by pirañas or water-snakes on the Reserve, or in the Great Ouse, you should inform the Environment Agency straight away as these are notifiable events.